SudoCue Users Forum Index SudoCue Users
A forum for users of the SudoCue programs and the services of SudoCue.Net
 
 FAQFAQ   SearchSearch   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

I am stuck

 
Post new topic   Reply to topic    SudoCue Users Forum Index -> Help Me! I'm stuck!
View previous topic :: View next topic  
Author Message
pjgrun
New kid on the Grid
New kid on the Grid


Joined: 03 Jun 2006
Posts: 2

PostPosted: Sat Jun 03, 2006 9:29 pm    Post subject: I am stuck Reply with quote

This puzzle is published in the sample section of "Solving Sudoku" document by Michael Mepham. Itīs rated tough, but even with the "diabolical" in the same section I was luckier.

. . 1|9 . .|. . 8
6 . .|. 8 5|. 3 .
. . 7|. 6 .|1 . .
-----+-----+-----
. 3 4|. 9 .|. . .
. . .|5 . 4|. . .
. . .|. 1 .|4 2 .
-----+-----+-----
. . 5|. 7 .|9 . .
. 1 .|8 4 .|. . 7
7 . .|. . 9|2 . .

After using some basic techniques and finned x-wing I arrive to

.------------------.------------------.------------------.
| 2345 245 1 | 9 23 7 | 56 456 8 |
| 6 249 29 | 1 8 5 | 7 3 249 |
| 23589 2589 7 | 4 6 23 | 1 59 259 |
:------------------+------------------+------------------:
| 1258 3 4 | 267 9 268 | 568 1567 156 |
| 1289 26789 2689 | 5 23 4 | 368 1679 1369 |
| 589 56789 689 | 367 1 368 | 4 2 3569 |
:------------------+------------------+------------------:
| 248 2468 5 | 236 7 1 | 9 48 36 |
| 29 1 2369 | 8 4 236 | 356 56 7 |
| 7 468 368 | 36 5 9 | 2 148 14 |
'------------------'------------------'------------------'

Here I am stuck! Any ideas?
Back to top
View user's profile Send private message
Ruud
Site Owner
Site Owner


Joined: 30 Dec 2005
Posts: 601

PostPosted: Sat Jun 03, 2006 11:42 pm    Post subject: Reply with quote

I can help you a little. When SudoCue reports a template check, I check for a Nishio style trick.

here it is:

Either R1C5 or C3C6 = 2.

When R1C5=2, R1C1 cannot be 2.
When R3C6=2, R7C4=2, R5C5=2, R4C1=2, R1C1 cannot be 2.
In both cases, R1C1 cannot be 2.

The next step must include a forcing chain or nice loop. I cannot find a simple one. Maybe one of our forum members can help us here.

Ruud
Back to top
View user's profile Send private message Send e-mail
GreenLantern
Regular
Regular


Joined: 30 May 2006
Posts: 14

PostPosted: Mon Jun 05, 2006 1:24 pm    Post subject: Reply with quote

Code:

+----------------------+----------------------+----------------------+
| 2345   245    1      | 9      23     7      | 56     456    8      |
| 6      249    29     | 1      8      5      | 7      3      249    |
| 23589  2589   7      | 4      6      23     | 1      59     259    |
+----------------------+----------------------+----------------------+
| 1258   3      4      | 267    9      268    | 568    1567   156    |
| 1289   26789  2689   | 5      23     4      | 368    1679   1369   |
| 589    56789  689    | 367    1      368    | 4      2      3569   |
+----------------------+----------------------+----------------------+
| 248    2468   5      | 236    7      1      | 9      48     36     |
| 29     1      2369   | 8      4      236    | 356    56     7      |
| 7      468    368    | 36     5      9      | 2      148    14     |
+----------------------+----------------------+----------------------+

[r1c1]=3=[r1c5]=2=[r5c5]-2-[r5c123]=2=[r4c1]-2-[r1c1] => r1c1<>2
[r7c4]=3=[r7c9]-3-[r8c7]=3=[r5c7]-3-[r5c5]-2-[r4c4]=2=[r7c4] => r7c4=23
[r7c1]=4=[r1c1]=3=[r1c5]=2=[r5c5]-2-[r4c4]=2=[r7c4]-2-[r7c1] => r7c1<>2
XY-wing (236): r7c24,r9c4 => r9c23<>6
X-wing in 3's: r67c49 => r5c9<>3
Coloring in 2's: r1c25,r7c24,r4c4,r5c5 => r235c2<>2
Coloring in 2's: r1c25,r2c3,r5c5 => r5c3<>2

Code:

+-------------------+-------------------+-------------------+
| 34    245   1     | 9     23    7     | 56    456   8     |
| 6     49    29    | 1     8     5     | 7     3     249   |
| 38    589   7     | 4     6     23    | 1     59    259   |
+-------------------+-------------------+-------------------+
| 12    3     4     | 27    9     68    | 568   1567  156   |
| 12    679   689   | 5     23    4     | 368   1679  169   |
| 5     679   689   | 37    1     68    | 4     2     369   |
+-------------------+-------------------+-------------------+
| 48    26    5     | 23    7     1     | 9     48    36    |
| 9     1     26    | 8     4     23    | 356   56    7     |
| 7     48    3     | 6     5     9     | 2     148   14    |
+-------------------+-------------------+-------------------+

[r2c3]=2=[r2c9]-2-[r3c9]=2|8=[r3c2]-8-[r3c1]-3-[r1c1]-4-[r2c2]-9-[r2c3] => r2c3<>9 and the puzzle solves.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SudoCue Users Forum Index -> Help Me! I'm stuck! All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group